238
FXUS66 KLOX 020350
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
850 PM PDT Sat Jun 1 2024

.SYNOPSIS...01/836 PM.

A persistent marine layer with cooler than normal weather will
remain in place through the weekend as strong onshore flow
continues across the area. High pressure aloft will build in next
week, weaken onshore flow, and bring a warming trend to area. The
hottest temperatures are expected for the interior portions of the
area Tuesday through Thursday.

&&

.SHORT TERM (SAT-TUE)...01/849 PM.

Another warm day across the interior, with some of the warmest
locations (including Antelope Valley) climbing to around 90
degrees. A weak upper level trough across the region combined
with a strong onshore flow pattern near the surface will continue
to bring a persistent marine layer presence. As of 8 pm,
satellite imagery showing a rapid surge of low clouds into coastal
and coastal valley locations. Current ACARS data showing the
marine layer depth around 1700 feet this evening across the LA
Basin. Little changes in temperatures expected on Sunday, then
gradual warming trend (especially interior areas) on Monday,
becoming more pronounced on Tuesday when warmest portions of
the Antelope Valley will be approaching 100 degrees.

The LAX-DAG gradient peaked at around +9 mb again this afternoon,
with similar gradients expected through Monday. Onshore wind
gusts between 25 and 35 mph have been common this
afternoon/evening across the interior, with local gusts to 45 mph
in the Antelope Valley foothills. Similar onshore wind gusts are
expected Sunday into Monday. The wind advisory for the Antelope
Valley will expire at 9 pm, but may need to be reissued for Sunday
afternoon/evening. The other area of wind concern tonight is
Southwest Santa Barbara county, where a wind advisory is in effect
until 3 am tonight for gusts up to 45 mph (strongest near
Gaviota/Refugio).

*** From previous discussion ***

High pressure tries to build over the area Monday, however, there
is one more weak trough that will pass through the West Coast,
keeping temperatures on the cooler side still. By Tuesday the
trough will be east of California. With weakening onshore flow and
a warmer air mass in place most areas should experience a warming
trend and much earlier clearing of the marine layer. The one
exception will likely be the immediate coast where onshore flow
and a strengthening inversion may keep low clouds lingering into
the afternoon. Coastal valley highs Tuesday should be close to 90
and even farther inland in the deserts temps should be close to
100.

.LONG TERM (WED-SAT)...01/209 PM.

The warmest day of this stretch will be Wednesday in most areas as
high pressure is at it`s peak locally and onshore gradients are
weakest. Still, due to the cold ocean SST`s and likely a strong
and low marine inversion, coastal areas temps will only rise to
around normal for this time of year. Inland temperatures, though,
will climb into the lower 90s for coast valleys and lower 100s for
the deserts.

A cooling trend will begin in most areas Thursday as high pressure
shifts east and onshore flow strengthens. By next Friday and
especially Saturday highs will again be 2-5 degrees below normal
for coast/valleys with a very likely return of a deepening marine
layer that will keep skies cloudy into the afternoon.

&&

.AVIATION...01/2309Z.

At 2215Z at KLAX, the marine layer was 2600 ft deep. The top of
the inversion was at 4800 feet with a temperature of 20 deg C.

Overall, moderate to high confidence in 00Z TAF package. High
confidence in return of CIG/VSBY restrictions to all coastal and
valley sites, but only moderate confidence in timing of flight
category changes (could be +/- 2 hours of current forecasts).

KLAX...Moderate confidence in 00Z TAF. There is a 40% chance that
IFR conditions will not develop overnight. Moderate confidence in
timing of flight category changes (could be +/- 2 hours of current
forecasts). No significant easterly wind component is expected.

KBUR...Moderate confidence in 00Z TAF. Timing of flight category
changes could be +/- 2 hours of current forecasts.

&&

.MARINE...01/836 PM.

In the northern outer waters zone (PZZ670), Gale Force winds will
continue tonight. Then, SCA conds are expected (80% chance) late
tonight thru Tue. There is a 40% chance gales Sun afternoon/eve.
There is a 50% chance of SCA conds Tue night/Wed morning. Conds
should then be below SCA levels Wed afternoon through Thu.

In the southern two outer waters zones, (PZZ673/676), SCA conds
will likely continue through at least late Monday night or
Tuesday. Conds should then be below SCA levels late Tue night
through Thu.

In the inner waters N of Pt. Sal, SCA level winds are likely (70%
chance) during the afternoon/eve hours today thru Mon and possible
thru Tue. Conds will then be below SCA levels Tue night through
Thu.

In the inner waters S of Pt. Sal, there is a 60% chance of SCA
winds in western portion of the SBA Channel during the afternoon
and evening hours through Mon. Otherwise, conds over the inner
waters should be below SCA levels thru Thu.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 3 AM PDT Sunday for
      zones 349-351. (See LAXNPWLOX).
     Wind Advisory remains in effect until 9 PM PDT this evening
      for zones 381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 645-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Sunday for zone 670. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/MW
AVIATION...RAT
MARINE...Gomberg/Sirard
SYNOPSIS...Hall

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox